Record Details
Selectivity and chemodynamics of 3,5-dibromo-4-hydroxybenzonitrile in winter wheat (Triticum aestivum L.) and coast fiddleneck (Amsinckia intermedia Fisch. & Mey)
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Selectivity and chemodynamics of 3,5-dibromo-4-hydroxybenzonitrile in winter wheat (Triticum aestivum L.) and coast fiddleneck (Amsinckia intermedia Fisch. & Mey) |
| Names |
Schafer, David Eugene
(creator) Chilcote, D. O. (advisor) |
| Date Issued | 1969-07-02 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Controlled environment chamber and laboratory studies were carried out to evaluate selectivity and chemodynamics of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) in winter wheat (Triticum aestivum L.) 'Nugaines', a tolerant species, and coast fiddleneck (Amsinckia intermedia Fisch. & Mey), a susceptible species. A comparison of ED₅₀ values, based upon reduction of whole plant growth, indicated that wheat was 109 times more tolerant of bromoxynil than was fiddleneck. The shoot/root ratios of both wheat and fiddleneck were observed to increase with increasing dosage of bromoxynil. Measurement of necrotic tissue weight of wheat and fiddleneck, as a function of bromoxynil dosage, suggested a sub-lethal translocation effect. The selectivity of bromoxynil in wheat and fiddleneck was concluded to be the result of a complex of interactions. Fiddleneck was found to retain twice as much spray solution as wheat. Mathematical analysis revealed that 6.3 percent of the differential toxicity could be attributed to differential herbicide retention. The penetration of bromoxynil-¹⁴C into leaf tissue was found to proceed more rapidly in fiddleneck than in wheat. Penetration of bromoxynil-¹⁴C could not be related to stomatal densities in either species. Only 4.9 percent of the selectivity existing between wheat and fiddleneck could be attributed to the penetration differential. Autoradiography and extraction procedures revealed that the label from bromoxynil-¹⁴C was more mobile in fiddleneck than in wheat. Higher levels of radioactivity were found in treated leaf, foliage and root extracts of fiddleneck as compared to wheat. Higher levels of insoluble label were found in treated leaves, foliage and roots of wheat as compared to fiddleneck. In both species, a high percentage of the extractable radioactivity was attributed to bromoxynil-¹⁴C. No specific difference in the percentage of total derivatives could be found. The evolution of ¹⁴CO₂ by wheat treated with bromoxynil-¹⁴C significantly exceeded that of fiddleneck. This indicated a greater capacity, on the part of wheat, to degrade this herbicide. Mathematical analysis indicated that 88.8 percent of the selectivity existing between wheat and fiddleneck could be attributed to internal physiological and biochemical mechanisms. |
| Genre | Thesis/Dissertation |
| Topic | Herbicides -- Toxicology |
| Identifier | http://hdl.handle.net/1957/45638 |
